Knowledge base
DNA, genes, cells, immunity, aging, and other concepts that make new research easier to understand.
19 explainersA typical honey bee drone has a mother but no father because it develops from an unfertilized egg and carries one chromosome set. Here is how that system works, why csd complicates the simple rule, and what it means for bee families.
Laboratory-made mRNA could trigger innate immune alarm signals. Karikó, Weissman and colleagues showed that changing the chemistry of RNA nucleosides could dramatically alter how immune cells recognized the molecule.
A pill does not search for the painful organ. After absorption, drug molecules circulate through the body, enter accessible tissues, interact with molecular targets, and are eventually metabolized and eliminated.
Different cells in the same woman can use different parental X chromosomes. X inactivation silences most of one X early in development, creating a lifelong cellular mosaic.
Vision is not a camera feed. The brain combines incoming sensory information with context and expectations, allowing us to interpret an incomplete world quickly — but sometimes producing remarkably convincing illusions.
Humans have 46 chromosomes while chimpanzees have 48 because two ancestral chromosomes fused to form human chromosome 2. The molecular traces of that event remain visible in our genome today.
Cells do not carry a miniature map of the future body. They infer their position from molecular gradients, neighboring cells and timing, then activate different genetic programs that gradually create organized tissues.
Most nucleated human cells contain roughly two metres of DNA. Nucleosomes and higher-order chromatin organization compact this enormous molecule into a microscopic nucleus while keeping the genome usable.
Relativity forbids any local object or signal from outrunning light, yet cosmological distances can grow faster than c. Here is what superluminal recession means and why some such galaxies remain observable.
Skin, intestinal tissue, and bone are continually renewed, yet the body still ages. We explain why replacing cells does not reset biological age and how cells, tissues, and repair systems change over time.
PET does not photograph a tumor. It maps the distribution of a radiotracer, revealing processes such as glucose use or activated tumor stroma—and not every area of high uptake is cancer.
Evolution is not a modern ape turning into a human or life marching toward perfection. This guide explains what changes across generations, how natural selection works, and why a scientific theory is not a guess.
what-is-cancer-how-it-develops
Information from a gene is first copied into RNA, which the cell then uses to build a protein.
A mutation is a change in the DNA sequence. One genetic “letter” may be replaced by another, or a section of DNA may be deleted, duplicated, inserted, or rearranged. Not all mutations have…
Epigenetics changes how cells use DNA without changing the DNA sequence itself.
An “on” gene is being used by the cell, while an “off” gene is largely silent.
Almost all cells contain the same DNA, but they function differently because different genes are active in them.
DNA, a gene, and the genome are related to each other, but they refer to different levels of organization of hereditary information. DNA is a long molecule in whose sequence biological…
